Crank-shaft-lubricating system



Sept; 29, 1925.

F. s. DUESENBERG CRANK SHAFT LUBR'IGATING SYS'iEH Filed April 11. 1522 Inveniorfiederubk *Silhwsenber-g Patented Sept. 29, 1925.

UNITED STATES FREDERICK S. DUESENBERG,

OF INDIANAPOLIS, INDIANA.

GRANK-SI-IAFT-LUBRICATING SYSTEM.

Application filed April 11, 1922.

To all whom it may concern:

Be it known that I, Fnnonnrox S. DUESEN- BERG, a citizen of the United States, and a resident of Indianapolis, Marion County, Indiana, have invented an Improvement in Crank-Shaft-Lubricating Systems, of which the following description, in connection with the accompanying drawings, is a specification, like characters on the drawings representing like parts.

This invention relates to crank-shaft lubricating systems of the class in which oil is conducted to the bearing surfaces of the crank-pins by conduits carried by the cranks, and the invention aims to improve the efliciency of such systems, to ensure an adequate supply of oil to the crank-pins at all times, to reduce the number of parts and joints, to make the crank-arms stronger and stiffer, to provide a simple and easily made construction which will not get out of order, and to lessen the weight of the crank-shaft as compared with other systems of this class. v

The invention will be best understood by reference to the following description, when taken in connection with the accompanying drawings of one specific embodiment thereof, while its scope will be more particularly pointed out in the appended claims.

In the drawings:

Fig. 1 is a central, longitudinal section of a portion of a crank-shaft exemplifying my invention, and

, Fig. 2 is a sectional view on line 22 of Fig. 1.

Referring to the drawings, and to the embodiment of the invention which is selected for exemplification, there is shown a portion of a crank-shaft having main bearing portions 4, crankpins 6 directly connected thereto by short crank-arms 8, and two crank-pins 10, which are directly connected to each other and are connected to the crank-pins 6 by long crank-arms 1-2.

The short crank-arms are provided with usual passages 14:, one of which is intended to receive oil-under pressure, usually fur nished by a pump not herein shown. These passages communicate with longitudinal passages 16 drilled axially in the crank-pms 6, and the latter in turn communicate with outlet passages 18 leading to the bearing surfaces of the crank-pins 6. Both ends of one passage 16 arelclosedby threaded Serial No. 551,487.

plugs 20 and 22, and one end of the other passage 16 is closed by a like plug 22.

Similarly, the crank-pins 10 have a common passage 24 extending axially therein and formed by drilling thereinto from one end thereof, the latter being closed by a threaded plug 26. The crank-pins 10 are provided with outlet passages 28 leading to their bearing surfaces.

If the passages 16 and 24 were connected to each other by passages extending through the main axis of the crank-shaft, the effect of centrifugal force would naturally tend to throw the oil outwardly in opposite directions from said axis. This difficulty is especially apparent in high speed motors, and requires a pump giving a very high pressure to ensure the delivery of an adequate supply of oil to the crank-pins. This difficulty is avoided by providing between the two crank-pins passages now to be described, which permit the oil to flow from one crank-pin to the other, without being obliged to cross-the main axis of the crankshaft.

Referring now to Fig. 2, each of the crank-arms 12 in the present example is provided with two sets of holes 30 drilled thereinto, each set comprising two holes disposed at an angle to each other, said sets being disposed at opposite sides, respectively, of a plane AA containing the axes of the crank-pins. Each of these sets of holes communicates with the other at two points adjacent the two crank-pins, respectively, as by providing chambers 32 formed by drilling radially into opposite ends of the crankarms 12. One convenient way is to drill the holes 32 first, and then drill the two holes 30 leading from each of the holes 32. The two holes 30 on each side of the plane AA are drilled to the proper depth to make them communicate with each other. Thus it is evident that the four holes 30 and the chambers 32 together afford a passage extending entirely about the main axis of the crank-shaft. It follows that the oil, in passing from one crank-pin to the other, travels in a path about the main axis of the crank-shaft, instead of across the latter, and in this way, the pressure required to force the oil through the system is very slight, while the distribution of the oil to the bearing surfaces is substantially uniform. v

The passages 80 communicate with the passages 16 by way of short passages 34 leading from the latter into the chambers 82, at the adjacent ends of the crank-arms. Similarly, the chambers 32 at the other ends of th crank-arms are connected by like passages 34 with the passage 24: in the crank-pins 10. The outer ends of the chambers 32 are closed by suitable plugs 36, herein provided with threaded shanks 38 screwed into radial openings 40. These shanks are smaller in diameter than the chambers, and therefore leave annular spaces which provide the necessary communication between the adjacent ends of the holes 30 and 84:. The heads of these plugs are shouldered, as at 4:2, and are seated upon suitable packing rings, herein copper and asbestos gaskets l i, which prevent the escape of oil. Each plug has suitable provision for turning the same, as by the provision of a polygonal depression 46. If desired, these plugs may be employed in obtaining the proper balance of the crankshaft, and mav be made in various weights according to the needs of the situation. Re moval of the several plugs enables the passages to be cleaned out very readily.

The described construction, while simple and easy to make, affords extraordinary stiffness, on account of the great width of the crank-arm at its central portion, yet is not unduly heavy. The number of separate parts is small, and there is no likelihood of the systems getting out of order.

Having thus described one embodiment of the invention, but without limiting myself thereto, what I claim and desire by Letters Patent to secure is:

1. A crank-shaft comprising one or more main bearing portions, a plurality of crankpins disposed about the axis of said main bearing portion or portions, said crankshaft presenting an oil conduit connecting two of said crank-pins and comprising two sets of drilled holes, each set comprising a plurality of intersecting holes disposed at an angle to each other, said sets being disposed at opposite sides, respectively, of a plane containing the axes of said two crankpins, and each set communicating with the other at two points adjacent said two crankpins, respectively, said sets affording a passage about said axis, clean-out openings affording communication between said holes and the exterior of said crank-shaft adjacent said crank-pins, respectively, and clean-out plugs normally closing said clean-out openings, respectively.

2. A crank-shaft comprising one or more main bearing portions,a plurality of crankpins disposed about the axis of said main bearing portion or portions, said crank-shaft presenting passages extending lengthwise of and within said crank-pins, respectively,two

passages intersecting each other, two passages leading from the said lengthwise passages, respectively, in outward directions with respect to the crank-pin axes, two chambers affording communication between the last-mentioned passages, and said intersecting passages, respectively, said chambers being more remote from the main bearing axis'than the point of intersection of said intersecting passages, and plugs closing communication between said chambers respectively, and the exterior of the crank-shaft.

3. A crank-shaft comprising one or more main bearing portions, a plurality of crankpins disposed about Said main bearing portion or portions, said crank-shaft presenting an oil conduit comprising passages extending lengthwise of and within said crank-pins, respectively, two sets of passages, each set comprising two passages disposed at an an gle to and intersecting each other, said. sets being disposed at opposite, sides, respectively, of a plane containing the axes of said crankpins, two passages leading from said lengthwise passages, respectively, in outward directions with respect to the crank-pin axes, two chambers affording communication between the last-mentioned passages, respectively, and passages of both of said sets, said chambers being more remote from the main hearing axis than said longitudinal passages, and plugs closing communication between said chambers, respectively, and the exterior of the crank-shaft.

4. A crank-shaft comprising one or more main bearing portions, a plurality of crankpins disposed about the axis of said main bearing portion or portions, said crank-shaft presenting an oil conduit connecting two. of said crank-pins and comprising two sets of drilled holes, each set comprising two holes disposed at an angle to each other, said sets being disposed at opposite sides, respectively, of a plane containing the axes of said crank-pins, each set communicating with the other at two points adjacent said crankpins, respectively, said sets affording a passage about said axis, and closure means adj acent said crank-pins closing communication between said holes and the exterior of the crank-shaft in a plane containing said axis and the axes of said crank pins.

5. A crank-shaft comprising one or more main bearing portions, a plurality of crankpins disposed about the axis of said main bearing portion or portions and presenting longitudinal passages, said crank-shaft presenting an oil conduit connecting two of said longitudinal passages and comprising two sets of drilled holes, each set comprising two holes disposed at an angle to each other, said sets being disposed at opposite sides, respectively, of a plane containing the axes of said two crank-pins, two chambers associated with said holes and disposed outward beyond and comunicating with said longitudinal passages, respectively, and in connection said holes afl'ording a passage about said axis, and two plugs closlng communication between said chambers, respectively, and the exterior of the crank-shaft.

6. A crank-shaft comprising one or more main bearing portions, a plurality of crankpins disposed about the axis of said main bearing portion or portions and presenting longitudinal passages, a crank-arm directly connecting two of said crank-pins to each other and presenting passages comprising two sets of holes at an angle to each other,

15 said sets being disposed at opposite sides,

respectively of a plane containing the axes of said two crank-pins and extending about the axis of said main bearing portion or portions, two chambers communicating with said holes and in connection therewith affording a passage about the axis of said main bearing portion or portions, said chambers also communicating with said longitudinal passages, and two plugs closing communication between said chambers, respectively, 25

and the exterior of said crank-shaft.

In testimony whereof, I have signed my name to this specification.

FREDERICK S. DUESENBERG. 

